Published online Jun 26, 2019. doi: 10.12998/wjcc.v7.i12.1444
Peer-review started: February 26, 2019
First decision: April 18, 2019
Revised: April 27, 2019
Accepted: May 2, 2019
Article in press: May 2, 2019
Published online: June 26, 2019
Currently, the findings about irisin as a novel myokine related to obesity are inconsistent in overweight/obese people. To our knowledge, no systematic analysis has been conducted to evaluate the relationship between irisin levels and overweight/obesity.
To evaluate the association between circulating irisin levels and overweight/obesity.
The Cochrane Library, MEDLINE, SCOPUS, and the ISI Web of Science were searched to retrieve all of the studies associated with circulating irisin levels and overweight/obesity. Standard mean difference values and 95% confidence intervals (CI) were estimated and pooled using meta-analysis methodology.
A total of 18 studies were included in our meta-analysis containing 1005 cases and 1242 controls. Our analysis showed that the circulating irisin level in overweight/obese people was higher than that in overall healthy controls (random effects MD = 0.63; 95%CI: 0.22-1.05; P = 0.003). In the subgroup analysis by ethnicity, the irisin level was higher in overweight/obesity people than that in controls in Africa (random effects MD = 3.41; 95%CI: 1.23-5.59; P < 0.05) but not in European, Asian, or American populations. In addition, in a subgroup analysis by age, the results showed that obese children exhibited a higher irisin level than controls (random effects MD = 0.86; 95%CI: 0.28-1.43; P < 0.05).
This meta-analysis provides evidence that circulating irisin is higher in obese individuals compared to healthy controls and it is important to identify the relationship between circulating irisin levels and overweight/obesity in predicting overweight/obesity.
Core tip: This study is the first meta-analysis that systematically assessed circulating irisin in overweight/obese people. This meta-analysis showed that circulating irisin levels were higher in obese individuals than in healthy controls. It also suggested that circulating irisin levels were higher in obese people in Africa than in controls. This meta-analysis further suggested that obese children exhibited a higher irisin level than controls.